What shifted

What kind of element moved in the captured layout shifts (heuristic, top-5 shifts per site).

Field data PhoneDesktopAll Scope All sites Q1 2026 edition · Phone field outcomes
Metric LCP INP CLS
1

At a glance the headline numbers for What shifted

What kind of element moved in the captured layout shifts (heuristic, top-5 shifts per site).

5
Categories
In the distribution
83.0%
Fleet share
Top: box_grow
52.5%
Sites with any
Of box_grow

2.0% of captured layout shifts trace back to unsized media. Font swaps account for 6.0%.

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
2

The what shifted mix who uses what, and how fast each group loads

Median INP (sites using feature)
0
100ms
200ms
300ms
400ms
500ms
Box grow100ms83% of sites
Displaced101ms8% of sites
Font text97ms6% of sites
Unsized media102ms2% of sites
Embed grow113ms1% of sites
VariantShare of sitesMedian
Box grow
83%
100ms
Displaced
8%
101ms
Font text
6%
97ms
Unsized media
2%
102ms
Embed grow
1%
113ms

What shifted. On the fleet: 83.0% box grow, 8.4% displaced, 6.0% font text. 52.5% of sites use at least one box_grow.

Lowest-share bucket: INP 97ms. Highest-share bucket: INP 100ms. r = +0.28.

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
3

Passing INP per bucket every category and count level at once - color is the pass rate

1
2
3
4
5
6
7
8
9
10
11
12
Box grow 83%
92
93
94
93
93
93
93
92
92
93
92
93
Displaced 8.4%
93
92
93
94
91
90
91
91
90
94
92
95
Font text 6%
92
93
92
94
93
93
95
94
94
94
94
95
Unsized media 2%
93
93
98
93
92
94
93
90
90
90
94
94
Embed grow 0.6%
93
93
92
88
93
91
83
← few of this category on the pagemany →
60%95%+ of sites passing INP Faded cells: under 100 sites

Each row is a category, each column its own count bucket (few on the left, many on the right); the cell is the share of those sites passing INP.

No category moves the INP pass rate much, however many a site ships. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
4

Few vs many - does quantity cost INP? the pass rate with few vs many of each category

60%70%80%90%100% few → many
Box grow 83% 92%93%
Unsized media 2% 93%94%
Displaced 8.4% 93%95%
Font text 6% 92%95%
% of sites passing INP · hollow ring = pages with few, solid dot = pages with many

Per category: the pass rate among pages with FEW of it (hollow ring) against pages with MANY (solid dot), worst trend first. Thin buckets are excluded from the endpoints.

Quantity barely moves INP here. The worst trend is Box grow, at 100 points. computed

The State of Web Vitals · Q1 2026 · 94,910 sites · phone field datacorewebvitals.io/state-of-cwv
5

Why this matters for the Core Web Vitals, and where to start fixing it

CLS tells you how much the page moved. This metric tells you what moved, and that decides the fix. An image without dimensions pushes everything below it down when it arrives. A swapped web font reflows whole paragraphs of text. An injected embed, banner or ad shoves the content aside after the page looked done.

Each element type has its own cure. Images need width and height so the browser reserves the box. Text needs a font-display strategy and a fallback font with matching metrics. Embeds and ads need a fixed slot that exists before they load. Identify the element first, then apply the matching fix.

How does this affect the Core Web Vitals?

Of the 5 categories, Embed grow separates passing sites from failing sites the most. Where Embed grow is rare: 87% pass the CLS. Where it is common: 55%.

Related signals Layout shift count → Shift direction → Largest single shift → Shift concentration → Chrome field data from 94,910 sites, representing millions of real page loads · How we measured